.block__banner{
    position: fixed;
    max-width: 430px;
    width: 100%;
    right: 5px;
    bottom: 5px;
    z-index: 100;
}

.btn__banner{
    padding: 10px 20px;
    display: block;
    margin: 0 auto;
    max-width: 388px;
    width: 100%;
    text-align: center;
    background-color: red;
    color: white;
}

.banner__img {
    max-width: 100%;
    height: auto;
}

.btn__close {
    background: none;
    border: none;
    border-bottom: 1px solid blue;
    color: blue;
}

.btn__close:hover {
    border-bottom: none;
    color: blue;
}

@media screen and (max-width: 768px) {
    .block__banner{
        max-width: 250px;
    }
}